1. Field of the Invention
The present invention relates to a lens-mounting structure that mounts a lens to a support portion using an adhesive agent, an optical-scanning apparatus that optically scans an image carrier, and an image-forming apparatus such as a copier, or printer and the like.
2. Related Art
In an image-forming apparatus such as a copier or printer and the like, an image carrier uniformly electrostatically charged by a charging device is optically scanned by an optical-scanning apparatus to form on a surface of the image carrier an electrostatic latent image that corresponds to image information.
Here, the optical-scanning apparatus is composed of a scanning optical system, installed in a frame, equipped with a deflector, such as a polygon mirror that deflects a light beam radiated from a light source, a scanning lens such as an fθ lens that converts the light beam deflected by the deflector into constant speed scanning light, and a plurality of reflective mirrors that guide the constant speed scanning light back onto a photoreceptor.
In this optical-scanning apparatus, a scanning lens is attached and installed in a housing support portion by adhesive. However, a problem existed in that desired optical characteristics could not be attained because of changes in a lens position caused by lens displacement associated with shrinkage that occurs because of adhesive agent hardening.
A lens-mounting structure has been proposed to reduce lens mounting direction displacement that occurs when the adhesive agent contracts, by forming a projection on a top surface of a support column of a mounting base and supporting the lens on the projection, and gluing a surface of the projection, and the peripheral portion of the contact portion with the top surface of the support column post and projection on the lens.